The control of emissions from internal combustion engines has received substantially continuous attention for many years in attempts to reduce emissions of carbon monoxide and unburned hydrocarbons from the combustion of such fuels. The control of pollution has received worldwide attention as attempts are made to fashion fuel additives that have the capability of making such liquid hydrocarbon fuels cleaner burning. Various approaches have been taken in the prior art in attempts to formulate additives that reduce the pollution generated by such fuels, but generally have met with limited success.
For example, it has been proposed to employ various alkyl ethers for the purpose of controlling pollution generated by gasoline fuels. Such attempts are described in U.S. Pat. Nos. 2,089,580, 2,104,021, 2,221,839, 2,563,101, 2,786,745, 2,930,681, 3,032,971, 3,103,101, 3,270,497, and 5,425,790, as representative. As described in those patents, it is frequently the practice to employ such ethers either alone or in combination with alcohol to provide improved performance characteristics in a variety of liquid hydrocarbon fuels.
Attempts have likewise been made to clean up such fuels by incorporating in the fuel as an additive various aromatic detergents containing one or more aromatic rings and bonded thereto various alkylene oxide groups in an effort to reduce hydrocarbon emissions. Such an approach is described in U.S. Pat. Nos. 3,328,284 and 3,615,295. The prior art has likewise proposed various combinations of additives to clean fuel systems. One such example is U.S. Pat. No. 3,658,494, describing a combination of oxy compounds in the form of monoethers of glycols and polyglycols in combination with dispersants derived from high molecular weight carboxylic acids, and particularly their esters, amides, imides, amidines and amine salts. U.S. Pat. No. 4,384,872 describes a fuel additive formulated of a lower alkanol combination with a surfactant to provide increased water tolerance in such fuel compositions. Similar approaches are described in U.S. Pat. No. 4,516,981, teaching an oil sludge dispersant formulated of an alcohol, a glycol ether and a poly ethoxylated phenol. And U.S. Pat. No. 4,877,416 teaching a combination of a hydrocarbon substituted amine or polyamine and a poly (oxy alkylene) monool.
Attempts have also been made to use oxidizing agents in combination with glycols and glycol ethers. One such example is described in U.S. Pat. No. 5,314,511, describing the combination of an organic peroxide in combination with a lower alkylene glycol ether to reduce emissions. U.S. Pat. No. 5,409,507 describes a fuel additive which is formulated of a nitro, amino or N-alkylamino-substituted poly (oxyalkylene) aromatic ethers in combination with antioxidants, metal deactivators, demulsifiers and like known additives. U.S. Pat. No. 5,782,936 describes a fuel additive for liquified petroleum gases or LPG containing a petroleum fraction methanol and an ethoxylated alkyl phenol.
Notwithstanding all of the efforts in the area of improving the performance of such fuels from a standpoint of pollution control, no product has been, up to the present, capable of satisfying rigorous pollution standard presently in effect or contemplated. Thus, there is a need to provide a fuel additive composition which has the capability of significantly reducing pollution from such liquified hydrocarbon fuels.
It is accordingly an object of the present invention to provide a fuel additive composition which overcomes the foregoing disadvantage.
It is another object of the invention to provide a method for the treatment of liquid hydrocarbon fuels which has the capability of significantly lowering the pollution characteristics of such fuels when used in internal combustion engines.
It is a more specific object of the present invention to provide a fuel additive composition which can be added to liquid hydrocarbon fuels to promote cleaner, more efficient combustion thereof in internal combustion engines.
It is another related object of the invention to provide a method for the treatment of liquid hydrocarbon fuels with a fuel additive composition whereby the pollution emitted by the treated fuel is substantially reduced.
These and other objects and advantages of the invention will appear more fully hereinafter by way of the following description of the invention.